fhemberger/gist:2665360

## gistfile1.html
<!DOCTYPE html>
<html>
    <head>
        <style>
            body { font-family: Arial, sans-serif; }
            th, td {
                text-align: center;
                padding: 10px;
            }
            th { background-color: #f0f0f0; }
            .true  { background-color: #e0ffe0; }
            .false { background-color: #ffe0e0; }
        </style>
    </head>
    <body>
        <h1>Loose comparison with == in JavaScript</h1>
        <table></table>
        <script>
            var comparisons      = [true, false, 1, 0, -1, "1", "0", "-1", null, undefined, [], {}, ""];
            var comparisonsTitle = ['true', 'false', '1', '0', '-1', '"1"', '"0"', '"-1"', 'null', 'undefined', '[]', '{}', '""'];
            var len              = comparisons.length;
            var html = '', bool;

            for (var y = -1; y < len; y++) {
                html += "<tr>";
                for (var x = 0; x < len; x++) {
                    if (y == -1) {
                        if (x == 0) { html += '<th></th>'; }
                        html += '<th>' + comparisonsTitle[x] + '</th>';
                    } else {
                        if (x == 0) { html += '<th>' + comparisonsTitle[y] + '</th>'; }
                        bool = comparisons[x] == comparisons[y];
                        html += '<td class="' + bool + '">' + bool + '</td>';
                    }
                }
                html += '</tr>';
            }
            document.getElementsByTagName('table')[0].innerHTML = html;
        </script>
    </body>
</html>
	<!DOCTYPE html>
	<html>
	<head>
	<style>
	body { font-family: Arial, sans-serif; }
	th, td {
	text-align: center;
	padding: 10px;
	}
	th { background-color: #f0f0f0; }
	.true { background-color: #e0ffe0; }
	.false { background-color: #ffe0e0; }
	</style>
	</head>
	<body>
	<h1>Loose comparison with == in JavaScript</h1>
	<table></table>
	<script>
	var comparisons = [true, false, 1, 0, -1, "1", "0", "-1", null, undefined, [], {}, ""];
	var comparisonsTitle = ['true', 'false', '1', '0', '-1', '"1"', '"0"', '"-1"', 'null', 'undefined', '[]', '{}', '""'];
	var len = comparisons.length;
	var html = '', bool;

	for (var y = -1; y < len; y++) {
	html += "<tr>";
	for (var x = 0; x < len; x++) {
	if (y == -1) {
	if (x == 0) { html += '<th></th>'; }
	html += '<th>' + comparisonsTitle[x] + '</th>';
	} else {
	if (x == 0) { html += '<th>' + comparisonsTitle[y] + '</th>'; }
	bool = comparisons[x] == comparisons[y];
	html += '<td class="' + bool + '">' + bool + '</td>';
	}
	}
	html += '</tr>';
	}
	document.getElementsByTagName('table')[0].innerHTML = html;
	</script>
	</body>
	</html>